(19)
(11) EP 0 414 643 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
12.08.1992 Bulletin 1992/33

(43) Date of publication A2:
27.02.1991 Bulletin 1991/09

(21) Application number: 90810620.6

(22) Date of filing: 16.08.1990
(51) International Patent Classification (IPC)5G05B 19/405
(84) Designated Contracting States:
AT CH DE ES FR GB IT LI SE

(30) Priority: 16.08.1989 US 394622

(71) Applicant: MEGAMATION INCORPORATED
Lawrenceville New Jersey 08648 (US)

(72) Inventor:
  • Pollack, Steven, H.
    Washington Crossing, Pennsylvania 18977 (US)

(74) Representative: Troesch, Jacques J., Dr. sc. nat. et al
Troesch Scheidegger Werner AG Siewerdtstrasse 95
8050 Zürich
8050 Zürich (CH)


(56) References cited: : 
   
       


    (54) Method and apparatus for monitoring and controlling linear motor robot apparatus and the like


    (57) A technique for preventing a stalled linear motor device from damage including monitoring accelerometer servos which generate signals representative of the difference between a command acceleration signal controlling the linear motor and the actual acceleration experienced by the linear motor device which signal represents the acceleration error and the direction of the error. The different signal is compared against programmed limits to develop a break-loose signal when the programmed limit (positive or negative) is exceeded. The break-loose signal is monitored as to duration, which duration is preprogrammed according to the dynamics of the system specifications presently in use. In the event that the break-loose signal exceeds the preprogrammed time limit, a latch is set, generating an interrupt signal applied to the computer control which immediately removes all motive power from the system and tests the latch to determine the source of the error, the latch remaining in the set state awaiting the computer test and being reset only after recognition by the computer.





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